Tuning the magnetic anisotropy via Mn substitution in single crystal Co4Nb2O9

Large easy-plane anisotropy induced spin reorientation in magnetoelectric materials (Co4−x Mn x )Nb2O9

“…Thus, a second kink comes into form around 60 K. We speculate that the second kink is due to a spin-reorientation transition. A firm understanding of this transition is still to be developed [14]. In order to confirm our speculation, we carried out neutron powder diffraction experiments for all these samples.…”

“…We speculate that these compositions have magnetic structures similar to the one of Co 4 Nb 2 O 9 . With increase of x, the kink shifts to higher temperature, indicating that Mn doping substantially increases the T N s of (Co 4−x Mn x )Nb 2 O 9 [14]. The other parent compound, Mn 4 Nb 2 O 9 , displays a totally different temperature dependency of magnetization along the a and c axes.…”

“…The powder samples were synthesized by using a standard solid-state reaction with Nb 2 O 5 , MnCO 3 and Co 3 O 4 powders as the starting materials. Single crystals of the corresponding nominal compositions were grown using a four-mirror optical floating-zone furnace in order to perform magnetization characterizations [14]. Synthesized pellets were ground into fine powders and loaded into vanadium sample cans for the diffraction experiment.…”

“…For applications, it would be much better to enhance its phase transition temperature since the Néel temperature (T N ) of Co 4 Nb 2 O 9 is not high. In this study, we demonstrate our efforts to increase T N by doping Mn in substitution for Co. On the basis of our magnetization measurements [14], we studied the magnetic phase transitions and magnetic structures of the (Co 4−x Mn x )Nb 2 O 9 series by using neutron diffraction. Both magnetization and neutron experiments show T N was substanti ally increased by substituting Mn 2+ for Co 2+ in Co 4 Nb 2 O 9 .…”

Polarized Hole Injection-induced Magnetic Enhancement in Carbon-Encapsulated Cobalt Ferrite Nanoparticles

“…The applications of magnetic nanomaterials in magnetic recording media, , micromagnetic devices, magnetoelectric materials, , microwave absorption applications, − biosensors, medical diagnostics, and therapy − have been comprehensively studied for decades. Spinel ferrites, a class of metal oxides with extraordinary physical properties, are the most extensively studied ferrimagnetic materials. , High-magnetization materials are particularly desirable for the development of advanced multifunctional magnetic applications.…”